This invention relates to lubricant compositions containing antioxidants and to new compositions of matter that are useful as antioxidants.
Organic compositions such as mineral oils and lubricant compositions are subject to deterioration by oxidation and in particular are subject to such deterioration at high temperatures and when agitated in contact with air. Most lubricating oils, greases, and hydraulic fluids as well as many other organic compositions contain additives to inhibit the oxidation thereof.
In U.S. Pat. No. 3,492,234 to Harry J. Andress, Jr. et al, there is described organic compositions that contain polyalkylated napthols having up to 30 carbon atoms per alkyl group, which organic compositions possess high temperature antioxidant properties at temperatures of 600.degree. F. and higher.
In U.S. Pat. No. 3,573,206 to Milton Braid et al, there is described lubricant compositions having improved antioxidant properties, which lubricant compositions contain oil-soluble products made by heating N-phenyl-naphthylamine, N-naphthyl-naphthylamine, mixtures thereof, or mixtures thereof with diphenylamine, in the presence of an oxidizing agent.
In U.S. Pat. No. 3,919,095 to Abraham O. M. Okorodudu, there is described organic compositions that contain esters of phosphorodithioic acids to provide increased oxidative resistance and antiwear properties.
In U.S. Pat. No. 3,497,181 to Milton Braid there is described organic substances that are protected from oxidative deterioration by the presence therein of minor amounts of aryloxy(alkyloxy)alkane.